In the formation of precision wound packages of glass fiber strands the glass strand being wound is produced by attenuating a multiplicity of glass filaments from a glass fiber forming bushing, gathering the filaments into a strand after application of a suitable binder to the filaments and winding the wet strand onto a forming tube carried on the winder surface. The finished package is normally cylindrical in shape and should have a flat surface with flat edges on either end. U.S. Pat. Nos. 3,367,587 and 3,365,145 describe a process for producing a precision wound package of the type contemplated by the process of the instant invention.
In modern commercial fiber glass forming operations, the fiber glass bushings used are becoming much larger in size and consequently can process more pounds of glass at a given drawing speed than the smaller bushing of past years. A fiber glass bushing is typically a container fashioned of precious metal, preferably platinum or a platinum-rhodium alloy. The container is usually open at the top and is attached to a source of molten glass. The bottom of the bushing is provided with a plurality of orifices or tips which are in open communication with the molten glass in the container. Glass flows through the orifice or tips to form the glass filaments. The filaments are attenuated from the bushing by gathering them into a strand and winding them at high speeds.
With the advent of the larger bushings now available, i.e., having 2,000 orifices or tips and the availability of precision winders capable of winding glass strand at speeds of 3,000 feet per minute or more, problems are created which seriously effect the production of satisfactory packages by processes heretofore used. The high glass pull rates, i.e., the pounds of glass filaments pulled from the bushing per unit of time, usually reported per hour, resulting from attenuating 2,000 filaments or more at speeds of 3,000 feet per minute or higher places great stress on the traversing guides used to lay the strand on the package. These stresses usually produce traverse vehicle deformation as the vehicle reaches the edge of the package and returns and this results in a rounding of the package edge which is undesirable. Since the packages are wound during the fiber glass forming operation, and since the strand as wound contains a binder which is applied as the filaments are being drawn, the packages contain considerable quantities of water, 10 to 15 percent by weight being typical. These packages must be dried before shipment. With large packages weighing 30 to 70 pounds and having moisture contents of 10 percent by weight or more, it is found that the drying operation often results in packages that encounter difficulty in the pay out of the strand when used. Thus, in removing the strand from the finished package, the strand will often stick to an adjacent strand thereby interrupting the smooth linear removal of the strand desired by the user.
These difficulties encountered have been minimized greatly by virtue of the novel traversing guide system of the instant invention and the processing steps taken prior to winding the strand on the packages with that traversing system.